This is the XTR FC-M985 Hollowtech Crankset with Hollowtech II bottom bracket. The XTR M985 is a race inspired 2x10 crank system with gear options for specific conditions. It features a Hollowtech II design for the optimum balance of lightweight and rigidity. The chain rings use HG-X to provide light action and reliable shifting. This crankset also has a narrower Q-factor crank arm.